Casio CZ/ VZ/ FZ - Pro Series

Yeah, that's somewhat interesting. They're less common but did crop up in a few synths from that time frame. I hadn't realised the CZ-1 used that topology, though - but I haven't done a lot of digging for its schematics (yet?). By my understanding, you're correct that anything with a coil/inductor will generally be more expensive than an equivalent made using R/C components. Mostly I see coils used for EMI filtering in synths of this sort of age - only in regions where legally mandated - and not for much else.